ABSTRACT
OBJECTIVE: The purpose of this study was to prospectively investigate the value of the myocardial extracellular volume fraction (ECV) in predicting myocardial functional outcome after revascularization of coronary chronic total occlusion (CTO). MATERIALS AND METHODS: Thirty patients with CTO underwent cardiovascular magnetic resonance (CMR) before and 6 months after revascularization. Three baseline markers of functional outcome were evaluated in the dysfunctional segments assigned to the CTO vessels: ECV, transmural extent of infarction (TEI), and unenhanced rim thickness (RIM). At the global level, the ECV values of the whole myocardium with and without a hyperenhanced region (global and remote ECV) were respectively measured. RESULTS: In per-segment analysis, ECV was superior to TEI and RIM in predicting functional recovery (area under receiver operating characteristic curve [AUC]: 0.86 vs. 0.75 and 0.73, all p values < 0.010), and it emerged as the only independent predictor of regional functional outcome (odds ratio [OR] = 0.83, 95% confidence interval [CI]: 0.77–0.89; p < 0.001) independent of collateral circulation. In per-patient analysis, global baseline ECV was indicative of ejection fraction (EF) at the follow-up examination (β = −0.61, p < 0.001) and changes in EF (β = −0.57, p = 0.001) in multivariate regression analysis. A patient with global baseline ECV less than 30.0% (AUC, 0.93; sensitivity 94%, specificity 80%) was more likely to demonstrate significant EF improvement (OR: 0.38; 95% CI: 0.17–0.85; p = 0.019). CONCLUSION: Extracellular volume fraction obtained by CMR may provide incremental value for the prediction of functional recovery both at the segmental and global levels in CTO patients, and may facilitate the identification of patients who can benefit from revascularization.
Subject(s)
Humans , Collateral Circulation , Coronary Vessels , Follow-Up Studies , Infarction , Magnetic Resonance Imaging , Myocardial Infarction , Myocardial Ischemia , Myocardium , Prospective Studies , ROC Curve , Sensitivity and SpecificityABSTRACT
Valvular heart disease (VHD) is one kind of the main causes of cardiovascular events in the elderly patients. Cardiac imaging evaluation plays a critical role in the diagnosis and selection of treatment options for VHD. New cardiovascular MR (CMR) techniques have been increasingly used for VHD patients, of which 4D Flow MRI-derived hemodynamic parameters can be used to estimate transvalvular blood flow velocities, pressure gradients, wall shear stress and flow patterns, T1 mapping and extracellular volume fraction enable quantification of changes of early ventricular remodeling secondary to VHD, strain analysis can be used to assess early myocardial dysfunction. The application progresses of new CMR techniques on VHD were reviewed in this article.
ABSTRACT
[Objective]We aimed to evaluate the role of contour-based registration in quantification of myocardial extracellular volume fraction(ECV)based on T1 mapping technique.[Methods]T1 mapping images of the basal,mid-cavity and apical short axis slices of 26 healthy volunteers(16 males and 10 females)were obtained before and after administration of contrast agent using Modified Look-Locker Inversion Recovery(MOLLI)on a 3.0T Magnetic Resonance Imaging system.ECV was calculated by routine method and registered method.For each slice,subjects were divided into the deformation subgroup and the control subgroup.Routine ECVs and registered ECVs were compared for each subgroup.[Results]Left ventricular deformation among T1 mapping images occurred in 16 subjects(61.5%). In all three slices, registered ECV maps had better image quality and more highest grade images than routine ECV maps. Routine ECVs[(26.81 ± 2.78)%,(25.38 ± 3.05)%,(28.66 ± 4.10)%]were statistically different from registered ECVs in global [(25.75±2.42)%,P=0.001],mid-cavity[(24.30±2.45)%,P=0.016]and apical slices[(27.22±3.38)%,P=0.010]. In deformation subgroups of all the 3 slices,registered ECVs were lower than routine ECVs with smaller SDs(P=0.038, 0.012,0.016).The apical ECVs were higher with larger SDs than the other two slices and the global ECVs(routine:F=4.799,P=0.004;registered:F=4.822,P=0.003).[Conclusions]Contour-based registration can improve the image qual-ity and precision of ECV quantification in cases with ventricular shape deformation among source images.